OT: Why do cars have Tachometers?

[Graham.]

I had a fridge / freezer with temperature displays that lied to me in a similar way. Spookily also made by Bosch.

[Graham.]

No it says : "Fifteen thousand, interlock ON".

Or maybe "Atomic batteries to power, turbines to speed".

[Graham.]

Even the most basic spec'd vehicles have one. I hardly ever look at mine, and the real-estate they occupy on the dash could be used for something useful.

I have just ordered a vehicle with a virtual dashboard (LCD screen) that I can configure sans rev-counter.

[Scott]

I sometimes wonder the same. I have never used one. I go by the sound of the engine.

[nothanks]

In my case (a hybrid) it tells me whether the IC engine is running or not, but a light could do the same and take less space.

[Scott]

Does it tell you the revolutions per minute of the internal combustion engine? Is this information useful in any way?

[Theo]

On some hybrids they've been replaced with an Eco-meter:

shows you how much energy is being consumed or regenerated. Staying at lower engine revs/more battery power is more efficient (the 'Eco' section).

There's usually a light to say if the IC is off (EV mode) as well.

Theo

[The Natural Philosopher]

I know that as long as keep it below 1500 I am not burning too much feul..

[John Rumm]

There was a time when many lacked them, but they seem to have become more ubiquitous over time. Presumably because many people like having them.

Maybe its a "detail person" thing, we just like having more information about what is going on.

Some might use it to help eek out the best fuel economy or performance.

Perhaps its just like the way people like VU meters and graphic equalisers on a HiFi even if they don't know what they are for either ;-)

There is some use - perhaps seeing how much headroom is available while contemplating a downshift at highish engine revs. Or judging the level of slip in your torque converter (for automatics that still have them).

[gopalansampath]

yes it is for me and Ishould think for every keen observing biped ! With a combination of info viz., for the same foot pedal travel an increase in rpm and less speed in kmph I would infer that-

my air filter needs to be looked at , either clean with forced air or replace

clogging in fuel filter or air/fuel mixer leading to change of filter or check readjust mixer and a hoard of diagnostic info can be available from dashboard.

For others, maybe, they would be happy to have the thumping noise from horse shoewith an occasional dropping sound of lumpy stuff !

PS Don't scream and demand my head, rather have a bit of humour in the new year !!

[Jim GM4DHJ ...]

they are only used by good drivers and never by wummin drivers....

[ARW]

It's for changing gear without using the clutch pedal:-)

Something that I always teach the apprentices.

[Jim GM4DHJ ...]

I for one can't drive a motorbike without one .....

[Scott]

Graham was referring to hybrid. Does a hybrid work in the way you describe? I thought the speed of the petrol engine - and indeed whether it is running at all - was all decided by software.

[Scott]

I would rather have an ammeter to assess whether the battery is charging or discharging and have an idea whether the battery and alternator are working properly.

[Brian Gaff (Sofa 2)]

To measure Tachs... erm... Does it say red alert just before the engine explodes? Brian

[Mr Pounder Esquire]

I've not played with that trick for over 30 years.

[The Natural Philosopher]

Once upon a time all cars of quality had tachos, water temperature gauges, oil pressure gauges, and battery charge/disharge meters, and speedometers.

Now they have warning lights instread on the basis that their owners are too stupid to handle detailed information abouit their engines.

Or they simply refuse to operate at all

[The Natural Philosopher]

What is this clutch pedal of which thou speakest?

[nightjar]

They are useful if you want to get the best out of a powerful car with a manual gearbox. Otherwise, they are superfluous.